Safety control

ABSTRACT

IMPROVED METHOD AND APPARATUS TO CUT OFF THE FUEL SUPPLY TO A LIQUID OR GAS FIRED HEATER IF SUCH HEATER IS DISLODGED IN ANY MANNER FROM THE POSITION WHERE IT IS INSTALLED.

June 20, 1972 SINK, JR" EFAL 3,671,170

SAFETY CONTROL Filed Jan. 11, 1971 E JAAAA) f lvLr/l/l/lfw ATTORNEY S Jm w T T N A W m D S EM Q C Al JR m Y B I: 6 3 ll n| 4 0 000 V%/ 6 O 3 4 United States Patent Oifice 3,671,170 Patented June 20, 1972 3,671,170 SAFETY CONTROL James A. Sink, Jr., and Richard J. Watson, Taylor's, S.C., assignors to Deering Milliken Research Corporation, Spartanburg, S.C.

Filed Jan. 11, 1971, Ser. No. 105,407 Int. Cl. F2311 /24 U.S. Cl. 431-88 4 Claims ABSTRACT OF THE DISCLOSURE Improved method and apparatus to cut off the fuel supply to a liquid or gas fired heater if such heater is dislodged in any manner from the position where it is installed.

This invention relates generally to a safety device and in particular to a safety device to cut off the fuel supply to a heater if it should be accidentally dislodged creating the possibility that the fuel line thereto may have been ruptured setting up a condition where possibly an explosion could occur. This condition could be very serious if a fuel such as natural gas, propane, etc. was being used.

Therefore, it is an object of the invention to provide a means to automatically shut off the supply of fuel to a liquid or gas fuel heater.

Other objects and advantages will become readily apparent as the specification proceeds to describe the invention with reference to the accomapnying drawings, in which:

FIG. 1 is a perspective view of a unit heater with the new and improved safety device;

FIG. 2 is a cross-section of the safety control shown in FIG. 1; and

FIG. 3 is the control circuit employed.

Looking now to FIG. 1, a gas or liquid fired unit heater is shown hung from a suitable support (not shown) by hangers 12. Mounted on top of the heater 10 is a control box 14 on which is mounted a relative motion switch 16. A swtich actuator follower 17 is mounted on the support 18 and is held in contact with the convex surface 20 of the switch actuator 21 of the switch 16 by fixed support 22 which can be the ceiling of the enclosure to be heated or other suitable rigid support provided for such purpose.

The switch actuator follower 17 can be a cylindrical member open at the bottom as shown in FIG. 2 or it can have a concave bottom which matches the convex surface of the switch surface 20 and nests thereon.

Looking now to FIG. 2, the switch 16 is shown in detail. The switch actuator 21 is biased upwardly by the spring 24 located in the groove 26 in the switch housing 28. Screwed to the underside of the switch actuator is contact disc 30 which engages the piston member 32 when the actuator 21 is tilted in any direction or moved downwardly to cause the piston member 32 to act against the bias of spring 34 to open the contacts 36. Contacts 36 are biased to the closed position by spring 38 held in the contact block 40 by suitable support 41.

As discussed previously, heaters and especially unit type heaters in a warehouse or other open spaces where hoist trucks and cranes are being moved constantly are in danger of being dislodged. When this happens it is very easy for a fuel line to be broken or split allowing fuel to either collect outside the heater or in the combustion chamber of the heater. Then an errant spark or match could easily ignite this fuel and cause an explosion which in turn could cause severe damage to personel as well as property.

The convex surface 20 of the switch actuator 21 is so designed that the slightest movement either sideways or vertically wall cause the actuator 21 to be pushed down so that the contact disc 30 will push the piston member downwardly against the bias of spring 34 to open the normally closed contacts 36. Looking at FIG. 3, opening of contacts 36 will deenergize a relay 42 thereby allowing its normally open contacts 44 to open and allowing normally closed contacts 46 to close. Closing of contacts 46 will then cause the solenoid 48 to close the fuel valve 50 and turn on the alarm 52.

To reset the circuit, reset button 54 is pushed thereby energizing the relay 42, since the contacts 36 are closed after repositioning of the heater 10. Energization of the relay 42 will then close contacts 44 and open contacts 46 allowing the fuel valve 50 to be opened to supply fuel to the heater 10.

It can readily be seen that the herein disclosed arrangement provides a safety system which automatically cuts off the fuel valve upon the occurrence of dislodgment of the heater to which it is supplying fuel.

Although we have described in detail the preferred embodiment of our invention, we contemplate that many changes may be made without departing from the scope or spirit of our invention and 'we desire to be limited only by the claims.

That which is claimed:

1. Apparatus to detect the movement of an object from a predetermined position comprising: an object, switch means mounted on said object, said switch means having an actuator with an upper convex surface, a fixed support and a follower supported at one end by said fixed support and pressing against the convex surface of said switch means to cause said switch means to be opened upon the movement of said object.

2. The apparatus of claim 1 wherein said follower has an open cylindrical end engaging said actuator.

3. The apparatus of claim 1 wherein said follower has a concave end mating with said convex surface of said actuator.

4. The apparatus of claim 1 wherein said object is unit heater having a fuel valve, said fuel valve being operably associated with said switch means and being closed upon the opening of said switch means.

References Cited UNITED STATES PATENTS 3,279,222 10/ 1966 Hebard 43 l--88 3,314,411 4/1967 Power 431-88 X 3,494,599 2/1970 Stupak et al. 43l88 X 3,511,585 5/1970 Liesse 43188 EDWARD G. FAVORS, Primary Examiner 

